And finally tonight, what it takes to be a hero. Today, the medal of honor was awarded to a soldier who was outnumbered and outgunned, and the video captured the video of what he did next. Abc's martha raddatz. Reporter: The sun had not yet risen when captain will swenson and his men made their way into an afghan village. That's when it happened. We start receiving fire. Reporter: An ambush. Pinned down, swenson returned fire for 90 minutes. His men hit. Sergeant first class kenneth westbrook, bleeding from the neck, losing consciousness. Bullets flying all around him. The enemy now so close, they called out for the americans to surrender. Swenson ran to westbrook, lobbing a grenade and carrying him the length of two football fields. A helmet cam captured the moment. That is swenson, his haelmet off. Risking his life by being out in the open, using an orange tarp to guide the helicopter in. He helps westbrook onto the helicopter, making sure he is secured. And then this. Watch. So quickly, so instinctively, swenson gives westbrook a tender kiss on his brow before racing back to the battle where he would help rescue others. I wanted to convey to him that I was proud of him and that his fight was over. That was an act that shows that bond that every soldier, every sailor, every airman and marine has with their fellow service member. Reporter: The story of captain swenson's heroism were lost for years in a tangle of army bureaucracy. Bull wh but what he did that day, in one of the deadliest regions in afghanistan, a place we have visited many times before, had to be recognized. The man swenson helped to that helicopter would eventually die, but at the white house today, his family and the families of the others captain swenson tried to help, were there to honor him. A soldier who risked everything for his brothers. Martha raddatz, abc news, washington. And a nation joins that salute.

This transcript has been automatically generated and may not be 100% accurate.

Capt. William Swenson Receives Medal of Honor Four Years After Surviving Brutal Firefight

Receives award for his courageous actions in Afghanistan four years ago.

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